WO2012050451A1

WO2012050451A1 - Marking system with chiral arrangement

Info

Publication number: WO2012050451A1
Application number: PCT/NL2011/050707
Authority: WO
Inventors: Aleksey Nikolaevich Simonov; Michiel Christiaan Rombach
Original assignee: Akkolens International BV
Current assignee: Akkolens International BV
Priority date: 2010-10-15
Filing date: 2011-10-17
Publication date: 2012-04-19
Anticipated expiration: 2013-04-15

Abstract

The invention provides a marking system for transparent objects comprising at least one arrangement of markers which arrangement comprises at least one marker, wherein the arrangement is a chiral arrangement adapted to provide a chiral function, with chiral function meaning that the chiral arrangement is adapted to provide orientation with regard to inversion, rotation and translation of, transparent, inversionally asymmetric objects. The invention also provides a transparent object comprising at least one marker to provide orientation with regard to inversion, rotation and translation of the objects in relation to a reference position, wherein the marker has a chiral structure adapted to provide a chiral function. Unambiguous positioning is relevant for objects with rotational asymmetry, inversional asymmetry and objects with a combination of rotational asymmetry and inversional asymmetry. In the latter case, the anterior and posterior surfaces of a transparent object have different functions and should be positioned accordingly.

Description

Marking system with chiral arrangement

Transparent objects (henceforth also: objects), present a unique challenge for orientation with regard to inversion, rotation and translation of the object, because it is impossible to, by only visual inspection, conclude whether a marker is positioned on the front side or back side of the transparent object. The present document discloses marking systems with chiral arrangements of markers to provide the desired, unambiguous, orientation or positioning of transparent objects with regard to inversion, rotation and translation of the object relative to a reference position. Unambiguous positioning is especially important for objects with rotational asymmetry and objects with inversional asymmetry and objects with a combination of rotational asymmetry and inversional asymmetry. In the latter case, for example, the anterior and posterior surfaces of a transparent object have different functions and should be positioned accordingly. Intraocular lenses (also: IOLs or lenses), are used in the present document to illustrate such marking systems with chiral arrangements, but the invention is not restricted to the application in such lenses. The marking systems according to the invention can also be applied to any other transparent object. Objects can be inversionally asymmetric, i. e. asymmetric with respect to the front/back inversion, for example, having front and back surfaces which are different. For example, an intraocular lens generally has a front side, i.e. the anterior surface facing the cornea, and a rear side, i.e. the posterior surface facing the retina and these sides should be properly positioned in the eye to provide the eye with the required

functionality of the lens.

Objects can also be rotationally asymmetric, i. e. asymmetric with respect to rotations in the plane of the object. For example, toric intraocular lenses, providing correction of the corneal astigmatism, have a designed direction, or alternatively, angular orientation, of implantation and positioning.

Objects can have supporting components, which can be rotationally and/or inversionally asymmetric. For example, intraocular lenses comprise haptics, to, for example, anchor the optical elements in the eye. Most such lenses must be implanted in the eye in the intended position with regard to rotation, inversion and translation to functioning properly.

In the present document, the XY-plane denotes the object plane and the Z-axis specifies the central axis, perpendicular to the object plane. In the case of an intraocular lens, the XY-plane is the plane of the optical elements; the Z-axis coincides with the optical axis. The triad XYZ forms a right-handed Cartesian coordinate system. In the context of the present document, rotation denotes the angular movement of an object in the XY-plane around the Z-axis. Inversion means that the object is flipped relative to the XY-plane, other words, the direction of the Z-axis is changed according to Z— > -Z . Translation is the movement of an object in the XY-plane.

Rotationally asymmetric objects have a distinct angular position, in the object plane, for the intended functionality. For example, a toric IOL should be angularly aligned with respect to the cornea. On the contrary, rotationally symmetric lenses, e. g. spherical IOLs, can be rotated around the Z-axis with no effect on the optical functionality.

Inversionally asymmetric objects have distinct front and back sides, or more generally, their functionality changes when Z— > -Z . For example, a thick plano-convex lens may result in different residual aberrations in the eye depending on the orientation of its spherical surface with respect to, for example, the cornea. Inversionally asymmetric intraocular lenses are, for example, lenses with two shifting optical elements as disclosed in, for example, US2010094413, WO201 1065833, WO201 1062486 and US2008046076. The marking systems described in the present document carry a chiral functionality. In mathematical terms, the marking system defined in the XY-plane is not invariant under parity transformations X— > -X or Y— > -Y which makes the identification of the object front/back side unique. Existing two-dimensional marking systems do not provide such a possibility and are invariant under parity transformations.

Marking systems according to the invention can comprise one complex marker adapted to provide said chirality, or, alternatively, a combination of at least two markers in a chiral arrangement. Markers can be dedicated markers, deliberately positioned on the object, for example, as engravings. Alternatively, markers can be inside the material of the object, for example, inserts of any size and made of any material. A single marker, as a part of the marking system, can be any geometrical structure, for example, a dot, a solid line, or a letter. Existing features of the object, for example, the asymmetry in the contour shape or the attachment of a haptic, can also have the additional function of marking. These marking features can be used in combination with the dedicated markers. The markers can be recognized visually, for example, by visual inspection, or tactilely, for example, by the surgeon before the surgery. The markers can also be designed such that their identification requires additional equipment and procedures employing, for example, ultrasound, or light, or X-ray radiation.

The marking systems for transparent objects should comprise at least one arrangement of markers which comprises at least one marker and which arrangement is a chiral arrangement adapted to provide a chiral function, with chiral function meaning that the chiral arrangement is adapted to provide the, desired and unambiguous, orientation, meaning orientation with regard to inversion, rotation and translation of transparent, inversionally asymmetric objects. The arrangement of markers can be any combination of markers and existing features of the objects as explained above. The term

'unambiguous orientation' means that one orientation of the chiral arrangement with regard to inversion, rotation and translation of the object corresponds to only one orientation of the transparent object with regard to translation, rotation and inversion. Proper orientation of the chiral arrangement, for example, by visual inspection, always corresponds to the desired object orientation of the. A chiral arrangement is an arrangement which can not be mapped onto its mirror image by any rotations and translations as illustrated in Figure 1 and as explained in M. Petitjean, J. Math. Phys. 43, 4147-4157, 2002.

Markers include dedicated markers and marking features. A dedicated marker is a feature which has no other function except for said marking, for example an engraved dot on the rim of the object. Marking features are existing features of the object which also provide for a marker, meaning an existing feature of the object which also provides a marking function in addition to at least other function. In the case of a lens, for example, a connection point of a haptic can double as a marking feature, see Figure 3. So, a marking system with chiral arrangement can comprises at least one dedicated marker, meaning a feature of the object which provides a marking function only, or, alternatively, can comprises at least one marker feature, meaning an existing feature of the object which also provides a marking function in addition to at least other function, or, alternatively, can comprise any combination of any number of dedicated makers and marker features.

The invention also relates to a marking system with chiral arrangement wherein the system comprises a combination of at least two singular markers which combination is adapted to provide said chiral function. It is however also possible that the system comprises at least one complex marker adapted to provide said chiral function.

Singular markers provide one point in space only, for example, a dot which indicates only rotational position of the object. At least two singular markers, for example, two dots, are required to produce a chiral arrangement of markers for said chiral function. The position of a singular marker is determined uniquely by the distance from the centre of the object, for example, the centre of the lens, and by the azimuthal angle measured from the reference direction, for example, the X-axis.

Complex markers, being a combination of multiple singular markers in a given plane of the object, can provide a combination of at least one point and at least one direction, for example a linear direction or the angular orientation of the object with regard to inversion, rotation and translation of the object. Complex markers can be provided by multiple singular markers or by a single complex marker. For example, an arrow marker, being a single complex marker, can indicate angular position, or azimuthal position, as well as orientation of the front/back side of the object, see Figure 4. Other examples of the complex markers, using a stripe and a letter, are shown in Figures 5 and 6. A chiral arrangement of markers can comprise two singular markers, or one complex marker, or any combination of singular markers and complex markers. Dedicated markers and marking features can be also combined in chiral arrangements, for example, by forming complex markers. Markers are generally located close to the periphery of the lens surfaces to reduce their effect, for example, scattering of light, on the optical function of the lens.

Accordingly the invention also relates to a transparent object comprising at least one marker to provide orientation with regard to inversion, rotation and translation of the objects in relation to a reference position wherein the marker comprising a

structure adapted to provide a chiral function.

The transparent object may for example comprise at least two markers of which at least one has a chiral structure to provide a chiral function, or at least one marker being a dedicated marker providing a marking function only. Another preferred embodiment provides the feature that in at least two of the markers form together a composite marker having a chiral function, with the transparent object being, for example, a component of an intraocular lens.

Subsequently the present invention will be explained with the help of the following figures, wherein show:

Figure 1 : a chiral marking system and its mirror image;

Figure 2: a chiral marking system with two markers;

Figure 3: a chiral marking system with one dedicated marker and two marking features;

Figure 4: a chiral marking system with a first complex marker;

Figure 5: a chiral marking system with a second complex marker; and

Figure 6: a chiral marking system with a third marker.

Description of figures

Figure 1 depicts a lens 1 , comprising three markers 2a, 2b and 2c, wherein the markers together form a chiral arrangement. Further a mirror 3 is shows just as a mirror image of the lens 1 with its markers 2. The mirror image comprises the mirror image 1 ' of the lens 1 and the mirror image 2a', 2b'and 2c'of the markers 2a, 2b, 2c. It is clear that the chiral structure and its mirror image can not be mapped on each other by any rotation and/or translation.

Figure 2 shows a lens 1 with two markers 2d, 2e, having a different azimuth and radius. Together these markers 2d, 2e form a chiral marking system.

Figure 3 shows a lens 1 with a single dedicated marker 2f, and two marking features which are formed by haptics 6 and 6b. Herein the marker per se 2f and the two haptics form a chiral marking system. Figure 4 depicts a lens 1 with a single complex marker in the form of an arrow 7. The arrow 7 itself has chiral properties so that it functions by itself as a chiral marking system.

A similar consideration counts for the lens 1 and the complex marker in the form of a stripe 8 depicted in figure 5.

This counts also for the lens 1 and the complex marker in the form of a letter 9 depicted in Figure 6.

So, marking systems with chiral arrangement object can comprises a chiral arrangement adapted to provide said chiral function for orientation of inversionally asymmetric intraocular lenses, as an aid for orientation during, for example, production of the lens, during packaging of the lens, at implantation of the lens during surgery and at evaluation of the lens, post-surgery.

Claims

1. Marking system for transparent objects comprising at least one arrangement of markers which arrangement comprises at least one marker, characterized in that the arrangement is a chiral arrangement adapted to provide a chiral function, with chiral function meaning that the chiral arrangement is adapted to provide orientation with regard to inversion, rotation and translation of, transparent, inversionally asymmetric objects.

2. Marking system as claimed in claim 1, characterized in that the system comprises at least one dedicated marker, meaning a feature of the object which provides a marking function only.

3. Marking system as claimed in claim 1, characterized in that the system comprises at least one marker feature, meaning an existing feature of the object which provides said marking function in addition to at least other function.

4. Marking system with chiral arrangement according to claim 1-3, characterized in that the system comprises a combination of at least two singular markers which combination is adapted to provide said chiral function, with singular marker meaning a marker which provides one position of one point.

5. Marking system with chiral arrangement according to claim 1-3, characterized in that the system comprises at least one complex marker adapted to provide said chiral function, with complex marker meaning a marker adapted to provide the combination of at least one point and at least one direction.

6. Marking system with chiral arrangement object according to foregoing claims characterized in that the system comprises a chiral arrangement adapted to provide said chiral function for orientation of inversionally asymmetric intraocular lenses.

7. Transparent object comprising at least one marker to provide orientation with regard to inversion, rotation and translation of the objects in relation to a reference position, characterized in that the marker has a chiral structure adapted to provide a chiral function.

8. Transparent object as claimed in claim 7, characterized in that the transparent object comprises at least two markers of which at least one has a chiral structure to provide a chiral function.

9. Transparent object as claimed in claim 8, characterized in that at least one marker is a dedicated marker providing a marking function only.

10. Transparent object as claimed in any of the claims 7-9, characterized in that at least two of the markers form together a composite marker having a chiral function.

11. Transparent object as claimed in any of the claims 7-10, characterized in that the transparent object is a component of an intraocular lens.

12. Combination of transparent objects as claimed in any of the claims 7-11, characterized in that the markers of each of the objects are separately distinguishable.